/ quickdraw to quickdraw

my friend was teaching me place nut/cams etc on the weekend and when I was going to extend my placement with just attaching a quickdraw to another(metal on metal) he stop me and told me I shouldn't do it.

I just went along with it and fumbled for a sling(I now know to rack them over my head).

Yes, as others have already said, metal to metal isn;t good as they could twist agaist each other and force one of the gates open <try it yourself at home>
If you really have to extend a QD and you have no slings, clip the second QD to the tape of the first QD, so, from your wire or whatever it'll go gear-crab-tape-crab-tape-crab.

Great picture in Ron Fawcetts old book, Climbing with Fawcett, he's on some blank face somewhere <stoney?> in the days before QD's and the gear he's clipped are clipped with 2 crabs simply clipped together! He's very much alive and well and never had a metal on metal disaster as far as I know but million to one odds are still pretty unjustifiable when it can be avoided so easily.

Get some 60cm slings and make up a few sling draws. These are like normal length quick draws but can extended out to 60cm long. Really versatile for trad climbing and always worth having a few on your rack

> You shouldn't clip snap gates to snap gates as there's a chance that they can twist and open against each other (when loaded).

> If desperate (no slings) then just take one carabiner out of a draw and clip the two together with just one in the middle.

Really....i do this occasionally and haven't had a problem. I suspect this advice comes from the pages of SPA 101 along with old chestnuts like avoiding "metal on metal". I'm not sure you could get the two draws to disconnect in laboratory conditions no matter how hard you tried so why worry about it on a route? The only reason I wouldn't do it was if a) I was redpointing the route and I wanted to maintain the alignment of the biner when extended or b) needed the extra crab on the rest of the route.

Clipping 2 quickdraws as you describe really shouldn't be a problem. The problem of krabs twisting against each other to unclip or bend the gates open only applies when there's no freeplay in the system which would be the case if you only had 2 krabs in total, not 2 quickdraws (i.e. 4 krabs + 2 short slings), especially if the 2 krabs were clipped into something fixed like a peg or a bolt.
Even then its more of a theoretical risk. You can see Ron fawcett doing this here at 17.15 mins (and elsewhere) http://www.google.co.uk/imgres?hl=en&biw=1024&bih=600&tbm=isch&tbnid=YPqcEDRwBz3OpM%...
The chances of krabs twisting open with 2 quickdraws are probably less than with one clipped in to a bolt.

> The chances of krabs twisting open with 2 quickdraws are probably less than with one clipped in to a bolt.

I can see that from the point of view of the shape of the bolt, but with two krabs there is already double the chance of it happening straight off the block. I'd put my money on the two krabs being worse.

Metal on metal does increase the shock load. I use linked carabiners to shock out a piece of kit once in awhile... try it, it works and if it doesn't it rips your nut in half.(probably not best practice)

also snap gates can warp under force in different angles. For example I have witnessed someone falling on a big HMS and bending it into an L shape. hence why snap gates over an edge are not recommended. simply they work best when used as advertised in the brochure.

The cause of breakage is if something rigid (i.e. a karabiner) should become twisted under the force of a falling climber via the rope against something which has no give in it e.g another karabiner or bolt. Hence 2 krabs clipped into a bolt, as in the Ron Fawcett video, poses a small but real risk. Its the rotational force which is the issue, not the downward force of the fall.
If the loaded krab is on a quickdraw you have a flexible nylon sling to twist so the twisting force isn't passed on to the other krab. If you have 2 quickdraws you now have 2 bits of nylon to twist so even less chance of the twisting force being transmitted to a krab. If those 2 quickdraws are clipped into the nylon sling of a Friend or wire of a nut you have even more stuff to twist.
2 quickdraws connected may be less tidy than a long sling and wasteful of quickdraws but it isn't dangerous.

Tripled draws are the way to go, but you need to read down to the very bottom of that article, where they provide links explaining why you shouldn't do what the the article says to do. Forget the rubber keepers.

It is true that carabiners can twist and come apart, but you can still find a lot of sport-climbing pictures in which clipped-together quickdraws are clearly featured.

In reply to Ban1: And if you know you are going to need some longer quickdraws and only have short sports ones, extend a few properly before you start - take the bolt end carabiner out to make a 'headless' quickdraw. Clip this into the rope end of a full quickdraw, so you have (from top to bottom) bolt end carabiner, sling, rope end carabiner, sling, rope end carabiner.

If you don't know which end the bolt end is, now would be a good time to learn! You should never ever clip anything sharp (bolts, pegs and wires) into the rope end of a quickdraw. It will put scratches in the carabiner which don't really reduce the strength of the carabiner but will cut through a rope in a fall.

Clipping carabiner to carabiner is just one of those things with definite, if small, risks and minimal benefit - just do it properly.

> Yes, as others have already said, metal to metal isn;t good as they could twist agaist each other and force one of the gates open <try it yourself at home>

> Great picture in Ron Fawcetts old book, Climbing with Fawcett, he's on some blank face somewhere <stoney?> in the days before QD's and the gear he's clipped are clipped with 2 crabs simply clipped together! He's very much alive and well and never had a metal on metal disaster as far as I know but million to one odds are still pretty unjustifiable when it can be avoided so easily.

Big Ron also does that in extremis on the Lord video as well. Was Pretty Standard Back in the day.

> ...It will put scratches in the carabiner which don't really reduce the strength of the carabiner but will cut through a rope in a fall.

Really?! IMO, a scratch is very, very unlikely to cut through a rope in the event of a fall! It might abrade the rope a bit, which over many repetitions could wear the sheath down a bit, but it's a pretty minimal risk. I've clipped draws the wrong way before, many times in fact, and it's not been catastrophic.

In reply to the OP, I've also clipped draw to draw before. Whilst I agree it's not ideal, in reality it's no biggie. As has been stated above, it's very unlikely to cause the gate(s) to open.

> (In reply to Ban1) You should never ever clip anything sharp (bolts, pegs and wires) into the rope end of a quickdraw. It will put scratches in the carabiner which don't really reduce the strength of the carabiner but will cut through a rope in a fall.
>
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> Really?! IMO, a scratch is very, very unlikely to cut through a rope in the event of a fall! It might abrade the rope a bit, which over many repetitions could wear the sheath down a bit, but it's a pretty minimal risk. I've clipped draws the wrong way before, many times in fact, and it's not been catastrophic.

Personally I'd be fine clipping snap gate to snap gate IF I was getting pumped and I didn't think I'd have enough time to organise clipping it to a sling or perhaps if clipping the sling didn't extend the placement enough and would otherwise mean loading a biner over an edge or similar. The actual risk for the most part of two biners clipped together unclipping them selves with modern floppy dyneema runners is pretty low (obviously depends on the cirumstance). I think you just need to assess the situation and make a judgement call.

From my point of view, I'd be concerned about the contact areas between the gear.

Using the simple stress equation: Stress (pressure) = force / area, a decrease in the area increases the stress.

If you were to put a krab through a krab, both have curved (convex) surfaces so the contact area will be incredibly small. This will increase the stress being applied to the krab(s).

However, if you put the krab through a sling, the sling deforms to the shape of the krab. This increases the contact area and reduces the stress applied to the krab.

I'm sure in reality people have fallen on gear (and it held) where they have connected two krabs together, but for me, placing gear is all about risk reduction and giving you the best chance of gear holding should you fall off!

Like sized/shaped krabs can un-clip one another quite readily. You can make a chain of draws quite safely of the form krab-sling-krab-sling-krab... It's a little messy looking with spare flappy krabs and nearly impossible with some dogbone slings but it avoids the krab-krab issue. Best is usually a long enough sling wit a krab each end.

In reply to knighty: "From my point of view, I'd be concerned about the contact areas between the gear."

You are worring about the wrong things, nearly all the bolts on portland are smaller diametre than a biner and round as are many pegs elsewhere. These work fine clipped by biners.

", placing gear is all about risk reduction and giving you the best chance of gear holding should you fall off!"

Yes, and that is complex to achieve and the correct course of action depends on the factors involved. A simple rule such as don't clip metal to metal or biners to biners doesn't work for that.

For example lets say you have no slings or quick draws or ways of making a quickdraw but needed to extend a nut, a reasonable way of doing this would be to link a few snap gates together, yes it wouldn't be as bomber as a quickdraw but it may well be the safest course of action.

> For example lets say you have no slings or quick draws or ways of making a quickdraw but needed to extend a nut, a reasonable way of doing this would be to link a few snap gates together, yes it wouldn't be as bomber as a quickdraw but it may well be the safest course of action.

If you were krab rich and needed to extend by using three snapgates in a row (as you describe), you could always have an opposed pair for the middle link... might go some way to making things a little safer. Though could perhaps cause some strange load case if the krabs are small.

In reply to crayefish:
The biggest risk I can see in linking krabs is that you have (potentially) less control of the orientation of the krab in a fall. The most likely failure point is cross loading of the krab or open-gate loading of the krab (should one krab lever the gate of the other open). Either significantly reduces the strength to a dangerous point.

It's all risk management though. We know what the ideal situation is (perfect length extenders, clipped neatly) - variations from that are often "normal" and needed in the real world, but it's important to know which risks you are increasing and which you are mitigating.

> IMO there is a massive difference between WILL cut the rope and CAN cut the rope.

True, hence my edit, but I doubt anybody really thought that I meant that if you put a scratch in a carabiner and run a rope over it it will cut the rope 100% of the time.

> I don't know anyone personally that has ever has a rope cut through yet I'm sure people break the rules regarding rope end biners fairly regularly.

I should hope not, since the result of that would be a good chance of them dying - the rope being one of the only non-redundant parts of climbing gear. However people have died from cut ropes as a result of sharp grooves in rope-end carabiners, albeit from wear not bolt scratches.

If you mean screwgates into bolts for belays etc, then the rope isn't running at high speed while loaded over the scratches; the rope is just clove hitched on or whatever.

It also matters what kind of bolts; Portland staples don't put any (non-cosmetic) scratches into my carabiners; my single trip to Cheddar on bolt hangers has significantly scratched several of my quickdraws. Equally round wires are going to be better than sharp-edged pegs.

> I don't even need to click on that link to see the word 'potential' in it.

And maybe if you did click that link you would learn what DMM mean by 'potential'? Specifically, they mean cutting entirely through the sheath in a low number of falls without a high fall factor (FF=0.4), purely due to the scratches in a carabiner.

In other words, you could destroy your rope if you just took a dozen or so falls, say while working a crux, onto a quickdraw that you had installed upside-down.

In reply to andrewmcleod: "However people have died from cut ropes as a result of sharp grooves in rope-end carabiners, albeit from wear not bolt scratches."

That case of rope grooves in biners was relevent nearly entirely to fixed gear on sports routes.

"If you mean screwgates into bolts for belays etc"
Not only that, I use my screwgates as emergency runners fairly regularly and they will go on either end of the runner! Albeit the times I do this I'm very very unlikely to fall off (I hardly ever fall on trad).

"It also matters what kind of bolts;"
I've climbed on most sort of bolts and fallen fairly often, none of my biners are badly damaged from that, but obviously this can happen.

If the krabs hang free of the rock in a potential fall, I can't see a problem with what you describe. If one of the krabs can be constricted then try to do something else. There is nothing inherently wrong with metal to metal though

> And maybe if you did click that link you would learn what DMM mean by 'potential'?

Life's too short already, sorry.

> In other words, you could destroy your rope if you just took a dozen or so falls, say while working a crux, onto a quickdraw that you had installed upside-down.

Not many folk work a bolted route on lead imo. I know I don't. I *could* destroy my rope, just like I *could* walk out the office and be hit by a falling anvil. I've had all my draws in 'upside down' at some point and very probably worked a route with the rope running through them. Guess it's a risk I'm prepared to take. Each to their own.

> Really....i do this occasionally and haven't had a problem. I suspect this advice comes from the pages of SPA 101 along with old chestnuts like avoiding "metal on metal".

Three years ago I was climbing at Portland and had just done the 3 star 7b Frazzled at Wallsend North. I clipped the staple bolts on the belay with a standard snap-link quickdraw then clipped myself into one of the carabiners using another standard snap-link quickdraw. I pulled through several meters of slack and was about to untie to thread the staples. Just before doing this I shifted my weight slightly to the right and the next minute I fell about 70ft down the full height of the wall pulling my belayer off the deck and stopping only 10ft from the ground. I dogged back to the belay half expecting to see the staple pulled or something similar but both of my quickdraws were clipped exactly as I had left them and both of the belay staple bolts were fine. The error was all mine, when I shifted my weight the snap-link had managed to twist and unclip itself resulting in the fall. I consider myself to be a reasonably experienced climber and have been climbing for 25+ years. What this taught me was (1) the way I threaded belays had become sloppy and potentially fatal (2) never never clip a snap-link carabiner into another even if you are simply extending a draw and (3) your never too old to learn by your mistakes. I had a very lucky escape!

Sounds like you had a very lucky escape. But just to clarify your experience: you imply it was the gate clipped directly into your harness which opened, rather than either of the linked crabs on the extended draws (connected directly metal to metal) which did. Is that correct?

To clarify; one quickdraw was clipped into the bolt and a second quickdraw had one end clipped into my harness and the other end clipped into the snap-link carabiner that I'd clipped to the bolt. It was the metal to metal link that twisted and unclipped so when I fell one draw was left on the bolt and the other draw was still attached to my harness. To elaborate further one of the staples had been drilled quite far in so the "eye" was very small and did not allow for much lateral movement. This probably contributed to the twisting motion required to unclip the two carabiners.

When you said in your first post: "I dogged back to the belay half expecting to see the staple pulled or something similar but both of my quickdraws were clipped exactly as I had left them", that sounded to me like the disconnection had happened between the harness and the draws. But you're now saying one of the draws was hanging off your harness. And you were only connected to one bolt at the lower off. Or maybe one QD in each bolt, and you had a 3rd QD linked to one (or both) of them, forming a Y shape?

I'm not trying to labour the point, just get a clear picture of what the anchor set up was.

You increase the point shock load and weaken the system. And Two pieces of metal banging together are more likely to fail then sling. Sure it's probably strong anyway but why would you- If you need to use multiple QDs (and the extendy system mentioned above is good to carry and reduces the likeleyhood), clip the second to the sling bit of the 1st rather then the krab. Also twisting could increase the chance of gate opening.

At the wall tonight I had a bit of a play. I clipped a snap gate to a bolt and another snap gate to the first. I then clipped a rope through the second carabiner. I then played with pulling, pushing and flicking the rope to try and make the two carabiners separate. It took awhile to find out how to do this, but once I could do it it became easy to repeat.

I have no idea how likely it is that this might happen in the real world, but as Lee has experienced above, if the carabiners are not both free the rotate, then it can occur.

> Maybe you should also edit "You should never ever clip anything sharp (bolts, pegs and wires) into the rope end of a quickdraw"

> "never ever"... . . really? and wires? c'mon, that is just rubbish!!

I stand by my statement - you should never clip the rope end of a quickdraw into something sharp. That is 'should', not 'if you clip the rope end of a quickdraw into a bolt you will DEFINITELY DIE' (which is also technically true but not the point!).

If you only clip your rope end into smooth staples like at Portland and undamaged wires, then you will never have a problem. Sharp bolt hangers can make a real mess though.

Quickdraws have a bolt/wire end and a rope end for a reason, what possible reason would you have for clipping them in the wrong way round when it is so easily avoidable and with a definite danger, or at least significantly degrading your rope? (for those to lazy to watch the video, DMM took a brand new rope and cut entirely through the sheath in a small number of factor 0.4 falls).

In reply to andrewmcleod: I've taken some pretty big lobs on to normal expansion bolts and I just checked my quickdraws on monday. There are no issues with the gear end biners that would cause a problem to a rope.

"I stand by my statement - you should never clip the rope end of a quickdraw into something sharp."

Sorry but that's not really what you said is it and its not how me or some of the other posters interpreted it.

"You should never ever clip anything sharp (bolts, pegs and wires) into the rope end of a quickdraw. It will put scratches in the carabiner which don't really reduce the strength of the carabiner but will cut through a rope in a fall."

This simply isn't true as myself and others have pointed out. I think it would be more accurate if you said:

"You should try and avoid clipping anything sharp into the rope end of a quickdraw. If you fall off it may put deep scratches and burrs in to the carabiner which don't really reduce the strength of the carabiner but can increase the risk of cutting through a rope in a fall."

I've fallen on to many bolts some of them expansion bolts, none of my gear end quickdraws would damage my ropes seriously at present if clipped in to the rope.

> Edit: where I said 'will cut through a rope in a fall', read 'can cut through a rope in a fall'.

From my second post in this thread. The difference between my statement (with this correction) and yours is merely semantics, although I cannot see a reason why 'try and avoid' is better advice than 'should not'? Perhaps there is a such situation, but I cannot think of it. We are in the 'starting out' part of the forum, after all.

In reply to andrewmcleod: "The difference between my statement (with this correction) and yours is merely semantics, although I cannot see a reason why 'try and avoid' is better advice than 'should not'?"

Try and at least quote your self correctly you said
"should never"

I think the main bone of contention most people have with your post is that you say:

"It WILL put scratches in the carabiner which don't really reduce the strength of the carabiner but WILL cut through a rope in a fall."

Anyway it doesn't really matter as you have cleared up what you meant now, just saying your original post was very definite about what WILL happen when in practice that's not what I've found. However the sentiment is correct (ie try and keep the rope and gear end of your quickdraws separate).

As a sub point I find if I am sharing gear with new partners the chance of the wrong end of the quickdraw being clipped to the gear / bolts is quite high, this hasn't caused me any problems.

What about those old school, gnarly trad-meisters who used to just clip a single crab through their pro / peg and clip the rope to that same crab? ie without any form of extender. When I first started, the guy I was climbing with did that quite frequently.

I suppose if we're being really picky, what you probably mean is "don't clip your rope into a crab that's been clipped into something sharp or scratched."

I think it's important to remember, in light of all of these comments, the difference between best practice and what people actually do/get away with. Climbing is about understanding and managing risk, as I'm sure you understand. Take as much info as you can from your own and other people's experiences, and from manufacturers' tests. Do you your own experiments like David (above). Appreciate the difference between manufacturers' recommendations/training bodies' best practice advice and the anecdotal experience of others. It doesn't matter if you've clipped draw-on-draw or single snaplink in a bolt for 20 years with no problems if you've never taken lobs onto that set up. That's where all this safety stuff matters. You can climb on a 50 year old rope if you want if you don't fall off! It's probably not putting the odds in your favour if you did one day fall off though.

I know people who are great at opening and eating packets of scotch eggs while driving (stearing with knees etc) and who've never had an accident. I wouldn't recommend it though, or say that it's fine....

> As a sub point I find if I am sharing gear with new partners the chance of the wrong end of the quickdraw being clipped to the gear / bolts is quite high, this hasn't caused me any problems.

That's one of the reasons all my quickdraws are silver/titanium at one end and yellow at the other. That way even the most careless of partners can handle the instruction 'only put the yellow end on gear!'

> (In reply to Doghouse)
> [...]
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> [...]
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> I stand by my statement - you should never clip the rope end of a quickdraw into something sharp. That is 'should', not 'if you clip the rope end of a quickdraw into a bolt you will DEFINITELY DIE' (which is also technically true but not the point!).

You said you should "never ever clip the rope end of a quickdraw into something sharp" which is blantantly bollox! Avoid, try not, check the krab afterwards if you ever do then maybe.. but "never ever" that's just not true.

> "It WILL put scratches in the carabiner which don't really reduce the strength of the carabiner but WILL cut through a rope in a fall."

You can't edit old posts though, so seems unfair to continue quoting this when I put the correction in my second post quite a considerable time ago!

> As a sub point I find if I am sharing gear with new partners the chance of the wrong end of the quickdraw being clipped to the gear / bolts is quite high, this hasn't caused me any problems.

You could apply this argument to anything though.

'If I am sharing gear with new partners the chance of them clipping in with a snapgate is quite high, this hasn't caused me any problems.
If I am climbing with new partners the chance of them building a terrible belay is quite high, this hasn't caused me any problems.
If I am climbing with new partners the chance of them accidentally unclipping me on a belay ledge is quite high, this hasn't caused me any problems.
If I am climbing with new partners the chance of them letting go of the brake rope is quite high, this hasn't caused me any problems.'

None of this makes it OK! Also I suspect in practice all climbers are likely to experience a cut single rope in a fall between 0 and 1 times... (with a few lucky exceptions)

In summary, you shouldn't do it and you should make sure no-one else you are climbing with does it either, which we agree on in principle if not in significance.

And in response to Fraser, yes I would avoid clipping my rope into a crab that has been clipped into something sharp; however, I recognise that this is a much harder thing to achieve. For example, it would be fine to clip into a belay anchor with some screwgates (as you are not falling on it) but it is a certain amount of faff to designate some screwgates for bolts/pegs/wires and some for soft goods etc etc. In some circumstances it would be safer/better to bring fewer screwgates, so the case here is not as clear-cut. But for quickdraws, there is a right way up and a wrong way up, and an obvious mechanism of failure (quickdraws regularly take falls).

In reply to andrewmcleod:
"In summary, you shouldn't do it and you should make sure no-one else you are climbing with does it either,"

I don't buy in to this I'm afraid.

To my mind a sling with two biners on it is a quickdraw and if I ran out of draws and snap gates but had a sling and two screw gates (or indeed two rope end snap gates) I'd personally make a quick draw up and use this to clip gear with. In this case you almost definitely should do it with the caveat that if you fall on it, it may be worth checking the biners for damage.

I think these black and white systems and best practices novices get taught are all good and well but in the real world when you have the knowledge and experience to make judgements for yourself many of the rules can be broken.

As a general rule, it is not (and is definitely not 'blatantly') balls. I still think it is valid, especially in context of the 'Starting Out' forum, and I said why - potential damage to the rope, not the carabiner. Personally I would never do it until the s**t was in danger of hitting the fan anyway, but all rules are made to be broken... doesn't mean it is a stupid rule!

You CAN do anything after all, doesn't mean you should... I don't think arguing (as stated, in the 'Starting Out' forum) that it is not a 'Really Bad Idea'® in general is helpful.

> potential damage to the rope, not the carabiner. Personally I would never do it until the s**t was in danger of hitting the fan anyway, but all rules are made to be broken... doesn't mean it is a stupid rule!

I'd agree with you that if possible, every step should be taken to prevent a scored krab being used where a rope would slide through it in a fall. But with modern 'unicore' ropes (I don't know if anyone other than Beal makes them but I am sure they do) if there are no 'rope' krabs left then clipping using a scored krab in an 'emergency' is not the end of the world as even if the sheath is stripped in a fall, the rope will still hold. Obviously it's not ideal to risk making your rope junk but sometimes there is no option.

Yeah. I suspect this is of much more relevance for sport climbing than trad. And one would have to be pretty negligent to not notice the damage on the rope after a couple of falls (ie. before the sheath fails).

But *maybe* in a trad/winter scenario, a scored krab combined with some drag over sharp rocks could be enough to split a sheath on a slightly worn rope. Pretty damn unlikely I know, but there are enough accidents due to that one-in-a-million scenario that I'd keep it in mind.

Years ago before quick draws were invented it was standard practice on long limestone routes with loads of peg protection to clip the ropes with two crabs on each peg. I learnt this from some pretty experienced French climbers who reckoned that this allowed the rope two run more freely. As I didn't have that many crabs I used to just clip into pegs with one.

Metal to metal didn't kill any of us, although one of them was killed a few years later by an avalanche, but that's another story.

> Years ago before quick draws were invented it was standard practice on long limestone routes with loads of peg protection to clip the ropes with two crabs on each peg. I learnt this from some pretty experienced French climbers who reckoned that this allowed the rope two run more freely...Metal to metal didn't kill any of us...I think some of you worry too much, or rather about the wrong things

Two carabiners on a piton wasn't uncommon in the US either back in the iron age. Then Mark Powell, who seemed destined to become one of the leading climbers of the day, suffered a terribly shattered ankle when he fell and his double-carabiner clip-in twisted and came apart. That shattered ankle completely changed the course of his climbing career and has been a significant problem for him for the rest of his life. Everyone I knew quit using two carabiners after that.

I think a lot of safety discussions are about things are about highly unlikely events. In the spectrum of things, I'd say two carabiners clipped together coming apart is unlikely but not extremely so. A lot depends on how much freedom of motion carabiners have---the more freedom the better. Mark's situation was the worst possible: the top carabiner had restricted motion by virtue of being clipped to the piton eye and the bottom carabiner transmitted rope motions directly to the top. With quick draws, I think the shorter and stiffer the quickdraws' slings are the better the chance of unclipping.

In climbing, the probability of catastrophe has to be weighed against how much trouble it is to protect against it. If the leader is using open slings, then it is just as easy to clip the second draw directly to the first sling as it is to clip metal to metal, and in that case it seems dumb to me to choose even a slightly more dangerous option.

> I'm not trying to labour the point, just get a clear picture of what the anchor set up was.

Correct! as I said in my post the way I was threading belays had become sloppy, I had opted for speed over safety. The other draw was going to be used to tie the rope off as I threaded by the way. This method, which I no longer adopt, was flawed throughout but the point I wanted to make was it is possible for two carabiner snap links to unclip given a particular set of circumstances.